Valuable vat dyestuffs of the dibenzanthrone and isodibenzanthrone series



Patented May 5, 1942 UNITED STATES PATENT OFFICE,

VALUABLE VAT DYESTUFFS OF THE DIBENZANTHRONE AND ISODIBENZAN- THRONE SERIES Otto Schlichting and Adolf Hrubesch, Ludwigshafen-on-the-Rhine, Germany, assignors, by mesne assignments, to General Aniline & Film Corporation, New York, N. Y., a corporation of Delaware No Drawing. Application May 28, 1940, Serial No. 337,662. In Germany June 24, 1939 6 Claims.

The present invention relates to new valuable vat dyestufis of the dibenzanthrone and isodibenzanthrone series, in particular to vat dyestuffs of the Bz2,Bz2'-diethyldibenzanthrone and the 322,322-diethylisodibenzanthrone series, and a process of producing same.

We have found that valuable vat dyestuffs of the dibenzanthrone and isodibenzanthrone series can be obtained by treating Bz2-ethylben-.

zanthrone, Bz2,Bz2 -diethyl-Bz1,Bz1 -dibenzan benzanthrone. The halogenated Bz2,Bz2-diethyldibenzanthrones dye vegetable fibers violetgrey shades whereas the corresponding halogenated dibenzanthrone dyes greenish blue; the halogenated Bz2,Bz2'-diethylisodibenzanthrones produce on vegetable fibers still more bluish thronyl or Bz2.Bz2'-diethyldibenzanthronylsulmay be varied within wide limits; the best results, however, are obtained by working at temperatures between 120 and 220 C.

For the purpose of halogenating the vat dyestuffs obtained by the alkali treatment they are brought into reaction either with free halogen, such as chlorine or/and bromine, or with compounds splitting ofi halogen under the reaction conditions, such as sulphuryl chloride, chlorsulfonic acid, ferric chloride or aluminium chloride. The halogenation may be carried out in the pres- .ence of organic solvents or diluents, such as trichlorbenzene or nitrobenzene, or of inorganic solvents, such as sulphuric acid, oleum, chlorsulphonic acid and the like, or also in aqueous suspension. In many cases it is preferable to employ promoters for halogenation, such as iodine,

sulphur, selenium, iron, antimony and the like.

Depending on the reaction conditions and the quantity of the halogenating agents employed there are obtained vat dyestuffs containing from one to four or more halogen atoms. By employing different halogenating agents there are obtained vat dyestuffs containing different halogen atoms, for example chlorine and bromine, in the same vat dyestufi molecule.

The dyestuff obtained by alkali treatment of BzZ-ethylbenzanthrone and Bz2,Bz2-diethyl- BzLBzl-dibenzanthronyl is Bz2,Bz2'-diethyldibenzanthrone, dyeing vegetable fibers pure blue shades, whereas the unsubstituted dibenzanthrone or Bz2,Bz2-dimethyldibenzanthrone dyes reddish blue shades. The end product of the alkali treatment of Bz2,Bz2'-diethyl-Bzl,Bzl'- dibenzanthronylsulfide is Bz,Bz2'-diethylisodishades than the unhalogenated compounds; in particular, the brominated Bz2,Bz2'-diethyli'sodibenzanthrones obtained by bromination of Bz2,Bz2'-diethylisodibenzanthrone in chlorsulphonic acid (lye vegetable fibers clear navy blue shades whereas the brominated isodibenzanthrones unsubstituted in the B22 and B22 position dye violet shades. As a rulewe found that by halogenating Bz2,Bz2'-diethylisodibenzanthrone in organic diluents, such as trichlorbenzene or nitrobenzene, there are obtainedvat dyestuffs which dye more greyish shades than the dyestuffs obtained by halogenating in inorganic solvents, such as chlorsulphonic acid or oleum. Furthermore, the brominated dyestuffs dye in many cases clearer shades of color than the chlorinated dyestuffs.

The new dyestuffs are clearly distinguished from similar known dyestuffs in that they produce dyeings which are not sensitive to spotting with water, have .a good, fastness to ironing, do not change their shade of color when washed or kier-boiled or treated with oxidizing agents, such as hydrogen peroxide, and are in many cases faster to weather than the corresponding known dyestuffs lacking the ethyl groups in Bz2 and Bz2'-position.

The following examples will further illustrate how the said invention may be carried out in practice, but the invention is not restricted to these examples. The parts are by weight.

Example 1 C 50 parts of BzZ-ethylbenzanthrone (melting point 119) are introduced at 100 C. into a melt and subsequently allowed to cool at C.,'

diluted with water, and, after adding some sodium hydrosulphite, filtered off. Air is, led through the. filtrate until the dyestuif hasseparated out and the precipitate is filteredv off. by

suction, washed with hot water until neutral. and

dried. After recrystallizing the product from trichlorbenzene, the Bz2,Bz2'-diethyldibenzanthrone is obtained in form of a bluish violet crystal powder having a bronze-colored luster and avmelting point of above 360 C. It dissolves in concentrated sulphuric acidgiving a redviolet coloration, in organic solvents, such as benzene, xylene and halogenbenzenes giving a redviolet coloration and a strong red fluorescencein' alcohols giving a blue-violet. and in glacial. acetic acid giving a blue coloration. "It dyes vegetable fibers from a pure blue vat navy blue shades which are not sensitive tospotting with water andhave a very good iastness to ironing.

, Example '2 v parts of B22322-diethyl-Bzl,Bz1'-dibenzanthronyl obtained by oxidation of BzZ-ethylbenzanthrone dissolved in 80'per cent sulphuricacid with manganese dioxide at from '50 to orange colored crystals showing 'the' 60 0.; melting point of 288 C.) are introduced into a 100 C, hot'melt of' 100 parts of potassium hydroxide" and 50 parts of methanol while stirring. The temperature is then raised to 140 C. Within an' hour and stirring is continued at this temperature for from 2 to 3 hoursfl The'reaction per cent aqueous solution of sodium sulfide, 1

containing dissolved some sulphur, -is heated in a closed vessel at from 130 to 140C; while stirring-until a sample contains no longer bromine. The reaction mixture isthen allowed -to cool, the separated precipitate is filtered off by suction, washed with water until neutral and dried. The Bz2,Bz2'-diethyl+Bz1,Bz1f-dibenzan thronylsulfide thus obtained in form of a yellow crystal powder has a meltingpoint of from 333 to 336 0. After recrystallization from' trichlor benzene there are-obtainew'y'ellow leaflets meltg 1 33 0 1 Y '125 parts of the BZ2;BZ2 diethy1-BZ1,BZ1"-di benzanthronylsulfide thus obtained are introducedat' from 100 to 110 C., while stirring into a meltpprepared from l'000 partsof potassium hydroxide and 500 partsof methanol. The temperature of the reaction mixture is then raised to 160 C. within one hour. and stirring is continued at'this temperature about 3 hours. After 'waterand 'the suspension is shortly'boiled while leading through air. The separatedblue dyestuff is, then filtered off by suction; washed with hot water until neutraland'dried. The Bz2,-;

B22diethylisodibenzanthrone is thus obtained Example 4 100 parts of Bz2,Bz2 diethylisodibenzanthrone (obtained according to Example 3) are idissolved in a solution of 1.3 parts of sulphur in I 1000' parts of chlorsulphonic acid. 33 parts of bromine are then vallowed to drop into this solution at from to C. and stirring is continued until free bromine can no longer be de- The reaction mixture is then diluted with 1000 partsof 96 per cent sulphuric acid, poured onto ice and the separated blue dyestuff is filtered ofi by suction, washed with water until neutral and dried. The dibrom-Bz2,Bz2-di ethylisodibenzanthrone thus obtained is a dark blue powder which dissolves in concentrated sulgood fastness to ironing. A

Example 5 I 20 parts of Bz2,Bz2'-diethyldibenzanthrone (obtained according to Example-1) are dissolved in a solution of 0.3 part of' sulphur in 200 parts of chlorsulphonic acid and 7' parts of bromine are allowed to flow into this solution at from 20 to 25 C. while stirring. Stirring is continued at this temperature for about 10 hours and the reaction mixture is worked up as describedin Example 4. The dibrom-Bz2,Bz2-diethyldibenzanthrone thusobtained is adark violet powder which dissolves in concentrated sulphuric acid giving a red-violet coloration. It dyes cotton from a blue vat grey-violet shades which are not sensitive to spotting with water andhave Employing 10 parts of bromine instead of '7 parts as described in the foregoing paragraph. there is obtained a vat dyestuff which dyes cot-.- ton, somewhat more reddish grey-violet.

Example 6 asuspension of 20 parts of Bz'2,Bz2-diethylisodibenzanthrone in 200 parts "of'nitrobenzene at 70 C. and stirring iscontinued for .2 hoursat 70- C. and then for 2 hours: at C. After cooling the separated dyestuff is filtered ofi :by suction, washed with nitrobenzene and methanol coolin to about 1,205 c. the melt is poured into and dried' A dark blue powder is thus Obtained which represents according; to analysis a tetra:- chlor Bz2,Bz2' diethylisodibenzanthrone. .It

dyes cotton from a blue vatgreyish violet shades ring and amixture of 24 parts of bromine and 70 parts of nitrobenzene areallowed to'flow into it.v After stirring for 8 hours at C.,t he re-. action mixture is allowed to cool and diluted with 2 50 parts of methanol. The dyestuff separating out is-filtered off by suction, washed with methe anol and dried. The dibrom-Bz2,Bz2'-diethyl isodibenzanthrone thus obtained is a dark blue powder which dyes vegetable fibers from a violetish blue vat neutral grey shades which are not sensitive to spotting with water and show a good iastness to ironing.

Example 8 A solution of 12.5 parts of Bz2,Bz2-diethyldibenzanthrone and 1.2 parts of iodine in 250 parts of 96 percent sulphuric acid is heated at 100 C. and 12 parts of bromine are allowed to flow into it while stirring. After stirring at 180 C. for about 6 hours, the reaction mixture is allowed to cool and poured into water. The separated dyestuff is filtered off by suction, washed with water, then with a dilute aqueous solution of sodium bisulphite, after this washed with water again and then dried. The dyestuff thus obtained dyes cotton from a blue vat brownish violet shades,

Example 9 9 parts of bromine are allowed to drop into a suspension of 13 parts of Bz2,Bz2'-diethylisodibenzanthrone in 250 parts of water at from 20 to 25 C. while stirring. After stirring at room temperature for about 20 hours, the dyestuff is filtered off by suction, washed with water until neutral and dried. A monobrom-Bz2,Bz2-diethylisodibenzanthrone is thus obtained which dyes cotton from a blue vat in navy blue shades being not sensitive to spotting with water.

Example 10 10 parts of bromine are allowed to flow into a solution of 10 parts of Bz2,Bz2-diethy1isodibenzanthrone and 1 part of iodine in 100 parts of chlorsulphonic acid at from 20 to 25 C. while densing agents at elevated temperature and halogenating the vat dyestufis thus obtained.

3. A vat dyestufi of the class consisting of B22,- Bz2-diethyldibenzanthrone and Bz2,Bz2-diethylisodibenzanthrone wherein up to four positions are occupied by halogen atoms selected from the class consisting of chlorine and bromine, the remaining positions by hydrogen.

4. The Bz2,Bz2-diethylisodibenzanthrone dyeing vegetable fibers from a blue vat brilliant blue-violet shades not sensitive to spotting with water.

5. A dibrom-Bz2,Bz2' diethylisodibenzanthrone dissolving in concentrated sulphuric acid giving a green coloration and dyeing vegetable fibers from a blue vat in navy blue shades not sensitive to spotting with water.

6. A monochlor-tribrom-Bz2,Bz2-diethylisodibenzanthrone dissolving in concentrated sulphuric acid with an olive-green color and dyeing vegetable fibers from a blue vat clear navy blue shades not sensitive to spotting with water.

OTTO SCHLICHTING, ADOLF HRUBESCH.

I CERTIFICATE OF CORRECTION. Patent No. 2,282,250. May 191 2.

CTTC SCHLIGHTING, ET AL.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 1, sec-- 0nd column, line 1, after "benzanthrone" and before the period insert the comma and words dyeing vegetable fibers more bluish ,violet shades than isodibenzanthrone or B22, Bz2 -dimethylisodibenzanthrone"; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the casein the Patent Office.

Signed and sealed this 28th day of July, A. D. 1912.

Henry Van Arsdale, Seal) Acting Commissioner of Patents. 

